阅读说明：本技术 套管扶正器 (Casing centralizer ) 是由 孙西宁 孙合平 刘东生 吕新明 袁振 高文亮 许兵 林云鹏 于 2020-08-05 设计创作，主要内容包括：本发明提供了一种套管扶正器,涉及油气井固井技术领域,包括第一环座、第二环座、若干个弓形弹片以及驱动组件；第一环座用于套设于套管的外周,第一环座的下端连接有连杆；第二环座用于套设于套管的外周,第二环座滑动连接于连杆上；若干个弓形弹片的两端分别与第一环座和第二环座相连；驱动组件设置于弓形弹片的内侧。本发明提供的套管扶正器,在套管以及套管扶正器向井内下入的过程中,弓形弹片处于收拢的状态,便于减小套管扶正器的外径尺寸,使套管顺畅的下入井内；当套管扶正器到达目的位置后,通过驱动组件对弓形弹片的内壁进行顶撑,使弓形弹片的外壁向外撑出,实现与井壁之间的有效顶紧,保证对套管可靠的扶正作用。(The invention provides a casing centralizer, which relates to the technical field of oil-gas well cementation and comprises a first ring seat, a second ring seat, a plurality of bow-shaped elastic sheets and a driving assembly, wherein the first ring seat is provided with a first end and a second end; the first ring seat is used for being sleeved on the periphery of the sleeve, and the lower end of the first ring seat is connected with a connecting rod; the second ring seat is used for being sleeved on the periphery of the sleeve and is connected to the connecting rod in a sliding manner; two ends of the plurality of bow-shaped elastic sheets are respectively connected with the first ring seat and the second ring seat; the driving assembly is arranged on the inner side of the arched elastic sheet. According to the casing centralizer provided by the invention, in the process that the casing and the casing centralizer are put into the well, the arched elastic sheet is in a furled state, so that the outer diameter size of the casing centralizer is conveniently reduced, and the casing can be smoothly put into the well; after the casing centralizer reaches the target position, the inner wall of the arched elastic sheet is propped through the driving assembly, so that the outer wall of the arched elastic sheet is outwards propped out, effective propping between the casing centralizer and the well wall is realized, and reliable centralizing effect on the casing is guaranteed.)

1. Casing centralizer, its characterized in that includes:

the first ring seat is sleeved on the periphery of the sleeve, and the lower end of the first ring seat is connected with a connecting rod extending along the axial direction of the first ring seat;

the second ring seat is sleeved on the periphery of the sleeve and is connected to the connecting rod in a sliding manner;

the two ends of the arched elastic sheets are respectively connected with the first ring seat and the second ring seat and are provided with outwards convex radians; and

the driving assemblies are respectively arranged on the inner sides of the arched elastic sheets and correspond to the arched elastic sheets one by one, and are used for outwards propping the arched elastic sheets.

2. The casing centralizer of claim 1, wherein the drive assembly comprises:

the fixing seat is arranged on the connecting rod in a spanning mode and is positioned on the inner side of the arched elastic sheet;

the middle part of the supporting rod is hinged on the fixed seat through a rotating shaft, and the outer end of the supporting rod is abutted against the inner wall of the arched elastic sheet; and

the fixed end of the telescopic piece is connected with the first ring seat, and the output end of the telescopic piece is abutted against the inner end of the supporting rod;

the support rod has a natural state separated from the telescopic piece and a top support state which is pushed by the telescopic piece to rotate around the rotating shaft to a horizontal position; when the supporting rod is in a propping state, the outer end of the supporting rod is abutted against the inner wall of the arched elastic sheet, and the arched elastic sheet is outwards propped.

3. The casing centralizer of claim 2, wherein the connecting rod is further provided with a guide groove on a side surface thereof, which is opened toward one side of the support rod, and is adapted to be slidably engaged with the inner end of the support rod.

4. The casing centralizer of claim 2, wherein the lower portion of the connecting rod is further provided with an elastic supporting member located below the rotating shaft and used for supporting the inner end of the supporting rod upwards.

5. The casing centralizer of claim 3, wherein the support rod is provided at an inner end with an arc transition and at an outer end with an arc extension for abutting against an inner wall of the arcuate spring.

6. The casing centralizer of claim 5, wherein the end of the telescoping member abutting the support bar is provided with a push plate.

7. The casing centralizer of claim 1, further comprising a plurality of guide blocks disposed at the outer periphery of the casing and between two adjacent bow-shaped spring plates, wherein the upper ends of the guide blocks are connected to the first ring seat, and rollers are further disposed on the outer side surfaces of the guide blocks.

8. The casing centralizer of claim 7, wherein an axially middle portion of the outer side surface of the guide block is outwardly convex, and a receiving groove for receiving the roller is provided on the outer side surface of the guide block, the roller being coupled to the receiving groove by a rotation shaft.

9. The casing centralizer of claim 7, wherein the rollers are disposed at least three on the guide block, wherein the roller at the middle portion is disposed to protrude outwardly from the other two rollers.

10. The casing centralizer of claim 7, wherein a deflector is further disposed on an outer side surface of the guide block, the deflector is inclined toward the same side of the guide block from top to bottom, and upper and lower ends of the deflector have tips, respectively.

Technical Field

The invention belongs to the technical field of oil and gas well cementation, and particularly relates to a casing centralizer.

Background

Along with the rapid development of oil gas development technology, the utilization of oil gas in social life is well guaranteed. After drilling of the oil and gas well is completed, a casing needs to be put in for well cementation operation. Casing centralizers are used to be installed on the outside of a casing and function to centralize the casing. In the process of cementing of a well cementation of an oil and gas well, a casing centralizer is usually installed on a casing string at intervals, so that the center of the casing and the center of a borehole are kept basically consistent, the replacement efficiency of the annulus cement slurry of the borehole can be improved, a uniform cement sheath between the casing and the borehole is ensured, the channeling of the cement slurry is prevented, and the casing jamming accident caused by the pressure difference of the casing is prevented.

The traditional casing centralizer has an elastic casing centralizer, a rigid casing centralizer, a rotational flow casing centralizer and the like, but when the elastic casing centralizer is in a horizontal well section, the centralizing effect is not ideal due to the influence of gravity, and the maximum outer diameter of the elastic casing centralizer is difficult to determine. If the external diameter of the elastic casing centralizer is too small, the centralizing force is insufficient, the elastic casing centralizer cannot play the role of the centralizer, and if the external diameter is too large, the casing centralizer scrapes the well wall when the casing is lifted up and down, the resistance is increased, and well cementation accidents are easily caused. Although the rigid casing centralizer has a good centralizing effect, the downhole resistance is large, and if the horizontal well section has borehole expansion conditions such as 'big belly' borehole diameter and the like, the centralizing effect is not ideal due to the limitation of the radial dimension.

Disclosure of Invention

The invention aims to provide a casing centralizer, and aims to solve the technical problems that the casing centralizer in the prior art is poor in centralizing effect and difficult to ensure well cementation quality.

In order to achieve the purpose, the invention adopts the technical scheme that: the casing centralizer is provided and comprises a first ring seat, a second ring seat, a plurality of bow-shaped elastic sheets and a plurality of driving components; the first ring seat is used for being sleeved on the periphery of the sleeve, and the lower end of the first ring seat is connected with a connecting rod extending along the axial direction of the first ring seat; the second ring seat is used for being sleeved on the periphery of the sleeve and is connected to the connecting rod in a sliding manner; two ends of the bow-shaped elastic sheets are respectively connected with the first ring seat and the second ring seat, and the bow-shaped elastic sheets are provided with outwards convex radians; the driving assemblies are respectively arranged on the inner sides of the arched elastic sheets and correspond to the arched elastic sheets one by one, and are used for supporting the arched elastic sheets outwards.

As another embodiment of the application, the driving assembly comprises a fixed seat, a supporting rod and a telescopic piece; the fixed seat is arranged on the connecting rod in a spanning manner and is positioned at the inner side of the arched shrapnel; the middle part of the supporting rod is hinged on the fixed seat through a rotating shaft, and the outer end of the supporting rod is abutted against the inner wall of the arched elastic sheet; the fixed end of the telescopic piece is connected with the first ring seat, and the output end of the telescopic piece is abutted against the inner end of the supporting rod;

the support rod has a natural state separated from the telescopic piece and a top support state which is pushed by the telescopic piece to rotate around the rotating shaft to a horizontal position; when the supporting rod is in a propping state, the outer end of the supporting rod is abutted against the inner wall of the arched elastic sheet, and the arched elastic sheet is propped outwards.

As another embodiment of the application, the side surface of the connecting rod is also provided with a guide groove which is provided with an opening facing one side of the supporting rod and is used for being in sliding fit with the inner end of the supporting rod.

As another embodiment of the present application, the lower portion of the connecting rod is further provided with an elastic supporting member located below the rotating shaft and used for supporting the inner end of the supporting rod upwards.

As another embodiment of this application the inner of bracing piece is equipped with the circular arc transition, and the outer end is equipped with the arc extension that is used for with the inner wall butt of bow-shaped shell fragment.

As another embodiment of this application, the one end that the extensible member and bracing piece butt are equipped with the push pedal.

As another embodiment of this application, the sleeve pipe centralizer still includes that a plurality of sets up in the sleeve pipe periphery and is located the guide block between two adjacent bow-shaped shell fragments, and the upper end and the first ring seat of guide block link to each other, still are equipped with the gyro wheel on the lateral surface of guide block.

As another embodiment of this application, the axial middle part of the lateral surface of guide block is outside protruding, is equipped with the holding tank that is used for holding the gyro wheel on the guide block, and the gyro wheel passes through the pivot to be connected in the holding tank.

As another embodiment of the application, at least three rollers are arranged on the guide block, wherein the roller positioned in the middle part protrudes outwards from the other two rollers.

As another embodiment of the present application, a guide vane is further disposed on the outer side surface of the guide block, the guide vane is inclined from top to bottom toward the same side of the guide block, and the upper end and the lower end of the guide vane have tips respectively.

The casing centralizer provided by the invention has the beneficial effects that: compared with the prior art, the casing centralizer provided by the invention has the advantages that in the process that the casing and the casing centralizer are put into the well, the arched elastic sheets are in a folded state, so that the outer diameter size of the casing centralizer is reduced conveniently, and the casing is smoothly put into the well; after the sleeve pipe centralizer reachd the target location, carry out the shore to the inner wall of bow-shaped shell fragment through drive assembly, make bow-shaped shell fragment axial length reduce, the outer wall outwards props out the effective top tight between the realization and the wall of a well, guarantee the reliable righting effect to the sleeve pipe, this sleeve pipe centralizer can be fit for the wall of a well internal diameter of different specifications, can realize strutting in good time of sleeve pipe centralizer according to work, be convenient for improve operating efficiency, guarantee to sheathed tube righting quality, have with low costs and convenient operation's advantage.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic cross-sectional view of an open state of an embodiment of a casing centralizer according to the present invention;

FIG. 2 is a schematic view of a partial enlarged structure of I in FIG. 1;

FIG. 3 is a schematic cross-sectional view of A-A of FIG. 1;

FIG. 4 is a cross-sectional structural schematic view of a closed state of an embodiment of a casing centralizer provided in accordance with embodiments of the present invention;

FIG. 5 is a cross-sectional structural schematic view of an open condition of an embodiment of a casing centralizer provided in accordance with the present invention;

FIG. 6 is a schematic top view of the structure of FIG. 1;

fig. 7 is a left side view of the guide block of fig. 1.

Wherein, in the figures, the respective reference numerals:

1. a first ring seat; 11. a connecting rod; 12. a guide groove; 13. an elastic top support; 14. a limiting plate; 2. a second ring seat; 3. an arched shrapnel; 4. a guide block; 41. a roller; 42. accommodating grooves; 43. a flow deflector; 431. a tip; 5. a drive assembly; 51. a fixed seat; 511. a rotating shaft; 52. a support bar; 521. an arc-shaped extending part; 53. a telescoping member; 531. pushing the plate; 6. a sleeve.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or be indirectly on the other element. It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be constructed in a particular operation, and are therefore not to be considered limiting. The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a number" means two or more unless specifically limited otherwise.

Referring to fig. 1 to 7 together, the casing centralizer according to the present invention will now be described. The casing centralizer comprises a first ring seat 1, a second ring seat 2, a plurality of bow-shaped elastic sheets 3 and a driving component 5; the first ring seat 1 is used for being sleeved on the periphery of the sleeve 6, and the lower end of the first ring seat 1 is connected with a connecting rod 11 extending along the axial direction of the first ring seat 1; the second ring seat 2 is used for being sleeved on the periphery of the sleeve 6, and the second ring seat 2 is connected to the connecting rod 11 in a sliding manner; two ends of a plurality of arched elastic sheets 3 are respectively connected with the first ring seat 1 and the second ring seat 2, and the arched elastic sheets 3 are provided with outwards convex radians; the driving components 5 are respectively arranged on the inner sides of the arched shrapnels 3, are in one-to-one correspondence with the arched shrapnels 3 and are used for supporting the arched shrapnels 3 outwards.

Compared with the prior art, the casing centralizer provided by the invention has the advantages that in the process that the casing 6 and the casing centralizer are put into a well, the arched shrapnel 3 is in a furled state, so that the outer diameter size of the casing centralizer is conveniently reduced, and the casing 6 is smoothly put into the well; after casing pipe centralizer reachd the target location, prop to the inner wall of bow-shaped shell fragment 3 through drive assembly 5, make bow-shaped shell fragment axial length reduce, the outer wall outwards props out the effective top tight between the realization and the wall of a well, guarantee to the reliable righting effect of casing pipe 6, this casing pipe centralizer can be fit for the wall of a well internal diameter of different specifications, can realize opening in good time of casing pipe centralizer according to work, be convenient for improve operating efficiency, guarantee to the righting quality of casing pipe 6, have with low costs and convenient operation's advantage.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1 to fig. 2, the driving assembly 5 includes a fixing base 51, a supporting rod 52 and an expansion member 53; the fixed seat 51 is arranged on the connecting rod 11 in a spanning manner and is positioned at the inner side of the arched shrapnel 3; the middle part of the support rod 52 is hinged on the fixed seat 51 through the rotating shaft 511, and the outer end of the support rod 52 is abutted against the inner wall of the arched shrapnel 3; the fixed end of the telescopic piece 53 is connected with the first ring seat 1, and the output end of the telescopic piece 53 is abutted with the inner end of the support rod 52;

wherein, the support rod 52 has a natural state of being separated from the telescopic member 53 and a top support state of being pushed by the telescopic member 53 to rotate around the rotating shaft 511 to a horizontal position; when the support rod 52 is in a propping state, the outer end of the support rod 52 is abutted against the inner wall of the bow-shaped spring piece 3, and the bow-shaped spring piece 3 is propped open outwards.

In this embodiment, the support rod 52 rotatably connected to the fixing seat 51 is used to support the bow spring 3 outwards. The support rod 52 is hinged to the fixing seat 51 through the rotating shaft 511, and the length of the support rod 52 located inside the rotating shaft 511 is smaller than the length of the support rod 52 located inside the rotating shaft 511, so that the lever effect of the support rod 52 on two sides of the rotating shaft 511 is facilitated, that is, the telescopic piece 53 pushes the inner end of the support rod 52 to move for a small distance, so that the outer end of the support rod 52 can prop the bow-shaped spring 3 for a large displacement. When the output end of the telescopic piece 53 moves downwards, the inner end of the support rod 52 can be pushed, the support rod 52 rotates anticlockwise around the rotating shaft 511, the outer end of the support rod 52 is abutted against the inner wall of the bow-shaped elastic sheet 3, the bow-shaped elastic sheet 3 is propped to an outwards propped state by the outer end of the support rod 52, the outer diameter of the bow-shaped elastic sheet 3 is increased at the moment, and effective jacking between the support rod and the well wall can be realized.

In the above-mentioned in-process, bow-shaped shell fragment 3 is outwards strutting the in-process, and bow-shaped shell fragment 3's lower extreme still can drive second ring holder 2 and upwards remove along connecting rod 11, and bow-shaped shell fragment 3 has different molding to different states under the prerequisite that has the same length, struts the in-process, and bow-shaped shell fragment 3's axial length shortens, and the external diameter grow guarantees to have reliable shoring effect to bow-shaped shell fragment 3, realizes the tight effect in top between bow-shaped shell fragment 3 and the wall of a well.

Further, the connecting rod 11 lower extreme is equipped with and is used for the limiting plate 14 with the second ring seat 2 matched with, under the prerequisite that 3 lower extremes of bow-shaped shell fragment and second ring seat 2 link to each other, has set up limiting plate 14 at the lower extreme of connecting rod 11. When the supporting rod 52 is separated from the pushing of the telescopic piece 53, the second ring base 2 moves downwards along the connecting rod 11, the limiting plate 14 can limit the limit position of the second ring base 2, the second ring base 2 is prevented from having too large downward pulling force on the bow-shaped elastic sheet 3, the damage to the bow-shaped elastic sheet 3 is avoided, and meanwhile, the matching relation between the second ring base 2 and the connecting rod 11 in sliding fit is ensured.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1 to 2, the side surface of the connecting rod 11 is further provided with a guide groove 12 having an opening facing one side of the supporting rod 52 and being configured to be slidably engaged with the inner end of the supporting rod 52.

In this embodiment, the guide groove 12 formed in the connecting rod 11 extends along the axial direction of the first ring seat 1, and can effectively limit the inner end of the supporting rod 52. When the output end of the telescopic member 53 extends outward, under the pushing action of the inner end of the support rod 52, the support rod 52 rotates counterclockwise around the rotating shaft 511, and the outer end of the support rod 52 pushes the bow-shaped spring 3 outward to be in a spread state. In the process that the supporting rod 52 rotates around the rotating shaft 511, the inner end of the supporting rod 52 is always kept in the state of being located in the guide groove 12, so that the outer end of the supporting rod 52 is prevented from moving relative to the bow-shaped elastic sheet 3, the outer end of the supporting rod 52 can effectively act on the inner wall of the bow-shaped elastic sheet 3, and effective jacking of the bow-shaped elastic sheet 3 is guaranteed.

Referring to fig. 1, 2, 4 and 5, as an embodiment of the present invention, the connecting rod 11 is further provided with an elastic supporting member 13 located below the rotating shaft 511 and used for supporting the inner end of the supporting rod 52 upward. In a natural state, the elastic supporting piece 13 has a certain supporting force on the inner end of the supporting rod 52, so that the inner end of the supporting rod 52 is stably located at a position higher than the rotating shaft 511, the outer end of the supporting rod 52 rotates to a state where the outer end is separated from the bow-shaped elastic piece 3 to the lower side, the axial length of the bow-shaped elastic piece 3 is increased, the outer diameter size is reduced, and the sleeve 6 can be conveniently and smoothly placed into the well.

Furthermore, the upper end of the elastic top supporting piece 13 can also adopt a form of abutting against the supporting rod 52, and an abutting groove can be further arranged on the side surface of the supporting rod 52 close to the elastic top supporting piece 13, so as to accommodate the upper end of the elastic top supporting piece 13, avoid the separation between the elastic top supporting piece 13 and the supporting rod 52, and ensure the top supporting effect of the elastic top supporting piece 13 on the supporting rod 52.

As a specific implementation manner of the embodiment of the present invention, please refer to fig. 1, fig. 4 and fig. 5, the inner end of the support rod 52 is provided with an arc transition, and the outer end is provided with an arc extension portion 521 for abutting against the inner wall of the bow-shaped spring 3.

In this embodiment, the arc transition is disposed on the side of the support rod 52 contacting the guide groove 12, and when the support rod 52 rotates around the rotating shaft 511, the arc transition portion at the inner end of the support rod 52 can avoid position interference with the accommodating groove 42, thereby improving the smoothness of the rotation of the support rod 52.

In addition, can also set up the elastic layer respectively at the inner and the outer end of bracing piece 52, the setting of elastic layer can avoid taking place rigid contact between bracing piece 52 and holding tank 42 or the bow-shaped shell fragment 3, is convenient for protect the inner wall of connecting rod 11 and bow-shaped shell fragment 3, avoids above-mentioned part to receive the damage, and then effectively improves the life of device.

When the telescopic member 53 supports the inner end of the supporting rod 52 downwards, the supporting rod 52 gradually rotates from a nearly vertical state to a horizontal state, and the elastic layer at the inner end of the supporting rod 52 is in contact with the inner wall of the accommodating groove 42. At this moment, the elastic layer is in a compressed state, a certain friction force is generated between the elastic layer and the support rod 52, and the support rod 52 can be stably positioned at the position by combining the top bracing effect of the push plate 531 at the lower end of the telescopic piece 53 on the support rod 52, so that the stability and reliability of the top bracing are ensured.

Further, the outer end of the support rod 52 is provided with the arc-shaped extension portion 521, and the arc-shaped extension portion 521 can enable the support rod 52 to have a smooth arc surface, so that the action area of force can be increased, the pressure of the local position on the arc-shaped elastic sheet 3 can be reduced, and the damage to the arc-shaped elastic sheet 3 can be avoided.

Referring to fig. 1, 2, 4 and 5, as a specific implementation manner of the embodiment of the present invention, a push plate 531 is disposed at one end of the telescopic member 53 abutting against the support rod 52. The push plate 531 can increase the area of the output end of the extensible member 53, can ensure the reliability of the extensible member 53 in pushing the support rod 52, and ensures that the extensible member 53 can reliably drive the support rod 52.

In combination with the arc transition portion arranged at the inner end of the support rod 52, the push plate 531 and the arc transition portion can be reliably abutted, so that the output end of the telescopic member 53 can be reliably driven to the inner end of the support rod 52 through the push plate 531, and further the effect that the support rod 52 rotates around the rotating shaft 511 is realized.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1, fig. 4 and fig. 5, the casing centralizer further includes a plurality of guide blocks 4 disposed on the periphery of the casing 6, the upper end of each guide block 4 is connected to the first ring seat 1, a roller 41 rotatably engaged with the guide block 4 is further disposed on the outer side surface of each guide block 4, and each guide block 4 is located between two adjacent bow-shaped spring pieces 3.

In this embodiment, still set up guide block 4 along the axial extension of sleeve pipe 6, at the sleeve centralizer along with the sleeve in-process of going into in the well, gyro wheel 41 can with take place the roll cooperation between the wall of a well, turn into the power of rolling with frictional force, play the effect that reduces frictional force between sleeve centralizer and the wall of a well, the income of sleeve pipe 6 of being convenient for.

In this embodiment, the guide block 4 extends along the axial direction of the sleeve 6 and is disposed between two adjacent bow-shaped spring pieces 3, and the guide block 4 and the bow-shaped spring pieces 3 are distributed at intervals in the circumferential direction. In the process of running the casing 6 into the well, the guide blocks 4 are distributed on the periphery of the casing 6, so that the whole circumferential direction of the casing 6 is guided. A plurality of bow-shaped shrapnels 3 are distributed on the periphery of the casing 6, after the casing 6 is placed to a certain position, the support rod 52 is driven by the telescopic piece 53 to rotate around the rotating shaft 511 to realize the propping of the bow-shaped shrapnels 3, and the effect of fixing the casing centralizer at the required position in the well is achieved.

As a specific implementation manner of the embodiment of the present invention, referring to fig. 1, fig. 4 and fig. 5, an axial middle portion of an outer side surface of the guide block 4 protrudes outward, a receiving groove 42 for receiving the roller 41 is disposed on the guide block 4, and the roller 41 is connected to the receiving groove 42 through a rotating shaft 511. The guide block 4 outside has set up the arch, and the arch can make the in-process of sleeve pipe centralizer in the well of going into has a process that gets into gradually, and the external diameter size at guide block 4 both ends is less than the external diameter size at guide block 4 middle parts, when going into sleeve pipe centralizer, utilizes the lower extreme and the wall of a well contact of little external diameter earlier, then utilizes the arch and the wall of a well contact of big external diameter, realizes good transitional action.

Furthermore, the guide block 4 is provided with an accommodating groove 42, a rotating shaft 511 for installing the roller 41 is arranged in the accommodating groove 42, the rotating shaft 511 can realize the rotating connection between the roller 41 and the guide block 4, and the roller 41 is sleeved on the periphery of the rotating shaft 511. A bearing may be disposed between the roller 41 and the rotating shaft 511 to reduce the friction between the roller 41 and the rotating shaft 511, thereby improving the smoothness of the rolling of the roller 41.

Furthermore, a plurality of rollers 41 are respectively arranged at the positions corresponding to different outer diameters of the guide block 4. In this embodiment, at least three rollers 41 are disposed on the guide block 4, wherein the roller 41 located in the middle portion protrudes outwards from the other two rollers 41. The setting is consistent with the convex setting, so that the smoothness of the casing 6 and the casing centralizer in the running-in process is ensured.

As a specific implementation manner of the embodiment of the present invention, please refer to fig. 7, a flow deflector 43 is further disposed on an outer side surface of the guide block 4, the flow deflector 43 is inclined from top to bottom to the same side of the guide block 4, and the upper and lower ends of the flow deflector 43 respectively have a tip 431. The spirally arranged flow deflector 43 has a spiral flow guiding effect on cement slurry, is used for guiding the flow direction of the cement slurry, can effectively reduce the frictional resistance and improve the well cementation quality.

Furthermore, the arrangement of the tip 431 is convenient for reducing the resistance of the flow deflector 43 when contacting with the slurry, so that the passing efficiency of the cement slurry is improved, and further the construction efficiency is improved.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.